Frequent coffee consumption linked to lower risk of early death

Research in the article “Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes,” a study published in BMJ and conducted by University of Southampton researchers, suggests that drinking up to four cups of coffee a day greatly reduces the risk of a premature death.

In August, a study conducted by the European Society of Cardiology found that drinking four cups of coffee a day decreases the chances of an early death. The research was based on observational data and was revealed at the European Society of Cardiology congress in Barcelona. The study involved 19,986 people who were tracked for an average of 10 years. Researchers from the Hospital de Navarra studied death rates, with 337 participants — around one in 60 of the entire group — dying during the period. The study concluded that those who drank coffee regularly had the lowest death rates, with the strongest relationship found among older participants.

In the University of Southampton study, which was conducted in November, researchers reviewed coffee consumption and its multiple health outcomes by systematically searching for meta-analyses in which coffee consumption had been part of a subgroup analysis. Meta-analysis is a technique that expands the reliability of research by merging the results of all the trials conducted. Seventeen meta-analyses that included data from clinical trials and 201 meta-analyses that included data from observational research were studied. These meta-analyses were examined using an umbrella review. Umbrella reviews combine previous meta-analyses and offer a descriptive summary of the research. In this case, researchers used an umbrella review to see the relationship between coffee and health benefits. Participants included people that were healthy, had pre-existing illnesses, pregnant, constant coffee drinkers and non-constant coffee drinkers.

The Univeristy of Southampton linked coffee consumption to a lower risk of heart problems, diabetes, liver disease and dementia. Coffee consumption was also linked to lower risks of multiple cancers, including prostate, endometrial, skin and liver cancer. The study also found a 17 percent lower risk of death among subjects who regularly drank four cups of coffee a day.

The health benefits of coffee were also discovered in two studies published in the journal Annals of Internal Medicine on July 10.

The first study, whose findings were published in the article “Coffee Drinking and Mortality in 10 European Countries: A Multinational Cohort Study,” analyzed more than 520,000 people from 10 European countries that were enrolled in the European Prospective Investigation into Cancer and Nutrition, making it the most extensive study on coffee and mortality to date. Researchers discovered a reverse link between coffee and liver disease, digestive diseases, circulatory diseases, suicide in men and cancer in women. Europeans who drank coffee also had lower levels of inflammation, indicating that coffee has anti-inflammatory properties that combat illnesses such as Parkinson’s disease. Participants also had better glucose control.

In the second study, whose findings were published in the article “Association of Coffee Consumption With Total and Cause-Specific Mortality Among Nonwhite Populations,” over 185,000 African-Americans, Native Americans, Hawaiians, Japanese-Americans, Latinos and whites living in Hawaii and Los Angeles participated. The results showed that the risk of death was reduced by 18 percent in people who drank two to four cups of coffee a day.

These findings revealed that even when conducting a study on diverse populations who sustain different lifestyles, the health benefits of coffee are still prevalent.

“These findings were consistent with previous studies that had looked at majority of white populations,” said Veronica Wendy Setiawan, associate professor of preventive medicine at Southern California’s Keck School of Medicine.

Scientists believe that coffee can extend life because the drink includes caffeine, diterpenes — a class of chemical compounds that include 20 carbon atoms — and antioxidants, natural chemicals found in food that impact health.

A lower risk of death from drinking coffee was also seen in smokers, which was a surprise for researchers since smoking is known to decrease human life span.

In the European study and predominantly non-white study,which were separate studies, smokers were separated from nonsmokers. Researchers also found that coffee had inverse effects on mortality for smokers.

Even though numerous reviews point to the benevolent effects of consuming this popular drink, coffee is not supposed to be used in place of medicine or to promote maintaining unhealthy habits.

“Although we can be assured that coffee intake is generally safe, doctors should not recommend drinking coffee to prevent disease, and people should not start drinking coffee for health reasons,” said Eliseo Guallar at the Johns Hopkins Bloomberg School of Public Health.

This means that smokers should not start drinking coffee or increase their consumption to counter the effects of their smoking.

Additionally, even though drinking coffee has been proven to be beneficial, the contrary can be said for pregnant women. The University of Southampton study found that drinking more than four cups a day is harmful during pregnancy, creating a risk of low birth weight, pregnancy loss, neural tubes in offspring and childhood leukemia.

Coffee consumption also has negative impacts for women with osteoporosis, a condition that leads to an increased risk of fracture.

The effects of coffee could also be countered if calorie-rich substances were added. Creams, sugars, unhealthy fats and flavoring could reduce the effects of coffee and expose drinkers to Type 2 diabetes. In other words, for the coffee to best affect health, it needed to be taken black.

Although the appeal of coffee is great during long nights, finals weeks and for the extra energy it may give, coffee should not be blindly depended on. Despite the study not finding any risks with drinking more than four cups of coffee a day, consumption should be carefully tracked.

While this study found a correlation between coffee and health benefits, it does not mean that being healthy is a causal effect of coffee. The study revealed that coffee drinkers were healthier than non-drinkers in the first place, and researchers did not recommend that non-coffee drinkers start drinking coffee solely for its health benefits.